In this work, we systematically study the mass spectra and strong decays of 1
P
and 2
S
charmed and charmed-strange baryons in the framework of non-relativistic constituent quark models. With the ...light quark cluster–heavy quark picture, the masses are simply calculated by a potential model. The strong decays are studied by the Eichten–Hill–Quigg decay formula. Masses and decay properties of the well-established 1
S
and 1
P
states can be reproduced by our method.
Σ
c
(
2800
)
0
,
+
,
+
+
can be assigned as a
Σ
c
2
(
3
/
2
-
)
or
Σ
c
2
(
5
/
2
-
)
state. We prefer to interpret the signal
Σ
c
(
2850
)
0
as a
2
S
(
1
/
2
+
)
state although at present we cannot thoroughly exclude the possibility that this is the same state as
Σ
c
(
2800
)
0
.
Λ
c
(
2765
)
+
or
Σ
c
(
2765
)
+
could be explained as the
Λ
c
+
(
2
S
)
state or
Σ
c
1
+
(
1
/
2
-
)
state, respectively. We propose to measure the branching ratio of
B
(
Σ
c
(
2455
)
π
)
/
B
(
Σ
c
(
2520
)
π
)
in the future, which may disentangle the puzzle of this state. Our results support
Ξ
c
(
2980
)
0
,
+
as the first radial excited state of
Ξ
c
(
2470
)
0
,
+
with
J
P
=
1
/
2
+
. The assignment of
Ξ
c
(
2930
)
0
is analogous to
Σ
c
(
2800
)
0
,
+
,
+
+
, i.e., a
Ξ
c
2
′
(
3
/
2
-
)
or
Ξ
c
2
′
(
5
/
2
-
)
state. In addition, we predict some typical ratios among partial decay widths, which are valuable for experimental search for these missing charmed and charmed-strange baryons.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We apply a new mass formula which is derived analytically in the relativistic flux tube model to the mass spectra of
Λ
Q
and
Ξ
Q
(
Q
=
c
or
b
quark) baryons. To this end, the heavy quark-light ...diquark picture is employed. We find that all masses of the available
Λ
Q
and
Ξ
Q
states can be understood well. The assignments to these states do not appear to contradict the strong decay properties.
Λ
c
(2760)
+
and
Ξ
c
(2980) are assigned to the first radial excitations with
J
P
= 1/2
+
.
Λ
c
(2940)
+
and
Ξ
c
(3123) might be the 2
P
states. The
Λ
c
(2880)
+
and
Ξ
c
(3080) are the good 1
D
candidates with
J
P
= 5/2
+
.
Λ
c
(3055) is likely to be a 1
D
state with
J
P
=3/2
+
.
Λ
b
(5912)
0
and
Λ
b
(5920)
0
favor the 1
P
assignments with
J
P
= 1/2
−
and 3/2
−
, respectively. We propose a search for the
state which can help to distinguish the diquark and three-body schemes.
A new strategy for enantioselective synthesis of axially chiral naphthyl‐indoles has been established through catalytic asymmetric addition reactions of racemic naphthyl‐indoles with bulky ...electrophiles. Under chiral phosphoric acid catalysis, azodicarboxylates and o‐hydroxybenzyl alcohols served as bulky but reactive electrophiles that were attacked by C2‐unsubstituted naphthyl‐indoles, which underwent a dynamic kinetic resolution to afford two series of axially chiral naphthyl‐indoles in good yields (up to 98 %) and high enantioselectivities (up to 98:2 er).
A new strategy for enantioselective synthesis of axially chiral naphthyl‐indoles was established by catalytic asymmetric addition reactions of racemic naphthyl‐indoles with bulky electrophiles. Under chiral Brønsted acid (B*−H) catalysis, azodicarboxylates and o‐hydroxybenzyl alcohols served as bulky but reactive electrophiles that were attacked by C2‐unsubstituted naphthyl‐indoles, affording axially chiral naphthyl‐indoles in good yields and enantioselectivities.
Selecting the newly observed Ξb(6227)− by LHCb as a study example, we decode its inner structure by giving the mass spectrum analysis and the investigation of its two-body strong decay behaviors. Our ...result indicates that the Ξb(6227)− is a good candidate of the P-wave Ξb′ state with JP=3/2− or 5/2−. In addition, we further provide the information of the properties of the partners of the Ξb(6227)−. These predicted states include three 2S states and the remaining 1P states in the bottom-strange baryon family. The calculated sizable Okubo-Zweig-Iizuka–allowed decay widths of these partners show that the experimental search for them becomes possible via LHCb. We have a reason to believe that the present study can be treated as a start point for constructing the highly excited bottom baryon spectroscopy.
Mortality from hepatitis B virus (HBV)–related acute‐on‐chronic liver failure (ACLF) is high due to limited treatment options. Preclinical and clinical investigations have proved that treatment with ...mesenchymal stromal cells (MSCs) is beneficial for recovery from liver injury. We hypothesized that the outcome of HBV‐related ACLF would be improved by MSC treatment. From 2010 to 2013, 110 patients with HBV‐related ACLF were enrolled in this open‐label, nonblinded randomized controlled study. The control group (n = 54) was treated with standard medical therapy (SMT) only. The experimental group (n = 56) was infused weekly for 4 weeks with 1.0 to 10 × 105 cells/kg allogeneic bone marrow–derived MSCs and then followed for 24 weeks. The cumulated survival rate of the MSC group was 73.2% (95% confidence interval 61.6%‐84.8%) versus 55.6% (95% confidence interval 42.3%‐68.9%) for the SMT group (P = 0.03). There were no infusion‐related side effects, but fever was more frequent in MSC compared to SMT patients during weeks 5‐24 of follow‐up. No carcinoma occurred in any trial patient in either group. Compared with the control group, allogeneic bone marrow–derived MSC treatment markedly improved clinical laboratory measurements, including serum total bilirubin and Model for End‐Stage Liver Disease scores. The incidence of severe infection in the MSC group was much lower than that in the SMT group (16.1% versus 33.3%, P = 0.04). Mortality from multiple organ failure and severe infection was higher in the SMT group than in the MSC group (37.0% versus 17.9%, P = 0.02). Conclusion: Peripheral infusion of allogeneic bone marrow–derived MSCs is safe and convenient for patients with HBV‐related ACLF and significantly increases the 24‐week survival rate by improving liver function and decreasing the incidence of severe infections. (Hepatology 2017;66:209–219).
Electrocardiographic imaging (ECGi) reconstructs electrograms at the heart's surface using the potentials recorded at the body's surface. This is called the inverse problem of electrocardiography. ...This study aimed to improve on the current solution methods using machine learning and deep learning frameworks. Electrocardiograms were simultaneously recorded from pigs' ventricles and their body surfaces. The Fully Connected Neural network (FCN), Long Short-term Memory (LSTM), Convolutional Neural Network (CNN) methods were used for constructing the model. A method is developed to align the data across different pigs. We evaluated the method using leave-one-out cross-validation. For the best result, the overall median of the correlation coefficient of the predicted ECG wave was 0.74. This study demonstrated that a neural network can be used to solve the inverse problem of ECGi with relatively small datasets, with an accuracy compatible with current standard methods.
Enantioenriched indole derivatives are widely found in natural products, pharmaceuticals and bioactive compounds. Therefore, developing efficient methods for the synthesis of enantioenriched indole ...derivatives has become an important goal in the community of organic chemistry. To this end, chemists have designed and developed a variety of indole-containing platform molecules and their related catalytic asymmetric reactions. Among these approaches, vinylindoles have proved to be versatile platform molecules for accessing enantioenriched indole derivatives via catalytic asymmetric reactions, especially organocatalytic asymmetric reactions. Based on this approach, a plethora of chiral indole derivatives have been synthesized with optical purity and structural complexity. This review summarizes advances in vinylindole-based organocatalytic asymmetric reactions since 2008 and includes the applications of some methodologies in the total synthesis of natural products. In addition, this review points out the remaining challenges in this research area to be confronted by organic chemists, which will shed light on the future development of this area.
Local lung microbiota is closely associated with lung tumorigenesis and therapeutic response. It is found that lung commensal microbes induce chemoresistance in lung cancer by directly inactivating ...therapeutic drugs via biotransformation. Accordingly, an inhalable microbial capsular polysaccharide (CP)-camouflaged gallium-polyphenol metal-organic network (MON) is designed to eliminate lung microbiota and thereby abrogate microbe-induced chemoresistance. As a substitute for iron uptake, Ga
released from MON acts as a "Trojan horse" to disrupt bacterial iron respiration, effectively inactivating multiple microbes. Moreover, CP cloaks endow MON with reduced immune clearance by masquerading as normal host-tissue molecules, significantly increasing residence time in lung tissue for enhanced antimicrobial efficacy. In multiple lung cancer mice models, microbe-induced drug degradation is remarkably inhibited when drugs are delivered by antimicrobial MON. Tumor growth is sufficiently suppressed and mouse survival is prolonged. The work develops a novel microbiota-depleted nanostrategy to overcome chemoresistance in lung cancer by inhibiting local microbial inactivation of therapeutic drugs.
Gas hydrate-caused pipeline plugging is an industrial nuisance for petroleum flow assurance that calls for technological innovations. Traditional thermodynamic inhibitors such as glycols and ...inorganic salts suffer from high dosing, environmental unfriendliness, corrosiveness, and economical burden. The development and use of kinetic hydrate inhibitors (KHIs), mostly polymeric compounds, with their inhibiting effects on hydrate nucleation and growth are considered an effective and economically viable chemical treatment for hydrate prevention. However, the actual performance of a KHI candidate is dependent on various factors including its chemical structure, molecular weight, spatial configuration, effective concentration, pressure and temperature, evaluation methods, use of other additives, etc. This review provides a short but systematic overview of the fundamentals of natural gas hydrates, the prevailing categories of polymeric kinetic hydrate inhibitors with proposed inhibition mechanisms, and the various synergists studied for boosting the KHI performance. Further research endeavors are in need to unveil the KHI working modes under different conditions. The conjunctive use of KHIs and synergists may facilitate the commercial application of effective KHIs to tackle the hydrate plugging problem in the oil and gas flow assurance practices.
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